ADV8005 down scalar poor quality

Discussion created by Srinivas on Feb 24, 2017
Latest reply on Mar 3, 2017 by JeyasudhaMuthuPerumal



We have ADV7619+ADV8005 on our platform. Output of ADV8005 goes to Application processor and then rendered on a 4K panel. Application processor can accept HDMI input up to 1080P resolution and then it will upscale to 4K to render it on a 4K HDMI panel. If input to the platform is 4K, ADV8005 will down scale to 1080P. We are seeing poor quality in case of 4K input.


We compared two cases:

Case 1 - Feed 4K HDMI signal from a PC. ADV8005 will down scale it to 1080P and the application processor will upscale it to 4K HDMI out.

Case 2 - Feed 1080P HDMI signal from same PC. ADV8005 will pass the signal as is to application processor which will upscale it to 4K HDMI out.


We see display output in case 1 is too poor when compared to case 2. Since application processor up scaling is involved in both cases, we believe ADV8005 scalar is not doing good job with down scaling.


We have done side by side comparison of the two cases using two setups. Attached image DCS_ScalingMD.PNG shows the quality difference. Left side of the image is for case 2 and right side of the image is for case 1. It can be clearly seen that right side of the image is too poor compared to left side of the image.


How can we improve the ADV8005 scalar performance? Are there any settings/registers exposed to play with for scalar improvements?


Software version:

  ADI VSP AVR Application Ver V1.90SP1
  HDMI-RX:  ADV7619 Rev 0x20c1
  HDMI-TX:  ADV8005 Rev 0x6083 without Rovi
  Created:  Feb 23 2017 At 17:51:10